Abstract: There are some main problems in the classification number of S82 and S83 coding of the CLC（5th Edition）, such as not agreement with natural science category coding principle, indicative imitation coding is not correct, the common name is not unified and some subtitles classification are too detailed. According to the CLC category of natural science coding principle from the general to points and from the general to the specific, made a specific practice for the standard coding of S82 and S83.

Key words: CLC